Impact of oral clomiphene citrate administration on prostatic volume and plasmatic testosterone concentrations in male beagles

Clomiphene citrate (CC) is a synthetic non-steroidal agonist/antagonist oestrogenic compound with reported agonistic properties on dogs’ male reproductive system. This protocol compared the impact of a 0.5mg/kg/day treatment of CC on plasmatic testosterone concentrations and prostatic volume (PV) on 2 groups of 5 young (<1.5years) healthy versus old (>8years) dogs with benign prostatic hyperplasia (BPH). Each dog was its own control and parameters were evaluated weekly over 2 periods of 8 weeks: 1 week pre-treatment, 3 weeks of treatment (placebo or CC) and 4 weeks post-treatment. Prostatic measures made by transabdominal ultrasonography were fed in the formula: (1/2.6 (lxLxh)) + 1.8) to calculate the PV (cm3). Plasmatic testosterone concentration (ng/ml) was measured by radioimmunoassay on samples obtained at the end of the morning. A linear mixed model was built and differences of least squares means were used to analyse the results and test the effects of treatment, week, age and their interactions. CC dogs have significantly lower PV values (10.36) than control dogs (12.91; p=0.01). CC old dogs have significantly lower PV values (15.05) than control old dogs (18.31; p=0.03). PV significantly (p=0.01) decreases in CC dogs from week 1 to 5 and then re-increases from week 6 to 8. CC dogs have significantly lower testosterone levels (0.7543) than controls (1.17; p=0.01). There is a significant interaction between the week and the treatment as shown by a transient decrease in testosterone similar to that of the PV. We conclude that CC decreases testosterone production and prostatic volume, which opens doors for BPH treatment.